Conventionally, in a granulation/coating apparatus (powder and particle processing apparatus) that performs granulation, coating, drying, and the like of a powder and particle, liquid spraying using a spray gun has been widely conducted. The spray gun of the powder and particle processing apparatus is typically disposed inside a powder and particle container. The spray gun uses compressed air to spray a fluidized or tumbled powder and particle with binder liquid or coating liquid (hereinafter, collectively referred to as “coating liquid”). Hot air or cold air is appropriately supplied/discharged to/from the container as air for drying (dry air) to promote formation or drying of a coating layer.    Patent Document 1: Jpn. PCT National Publication No. 2003-525746    Patent Document 2: Jpn. Pat. Appln. Laid-Open Publication No. 2001-137747    Patent Document 3: Jpn. Pat. Appln. Laid-Open Publication No. 2003-220353